Post Christmas Post

I spent Christmas in Dublin. My wife's parents live near a place called Sandy Cove, famous for its Martello tower that features in the opening pages of Ulysses. Next to the tower is an early Modernist house by Michael Scott whose curving balconies subtly echo the circular form of its neighbour.

Both buildings look down on the 40 ft, an outcrop of rock which is a popular swimming spot and the place where Buck Mulligan takes a dip at the beginning of Ulysses. The 4o ft forms a natural diving point but the rocks have been sculpted to form steps and there are railings that lead down into the water. Concrete changing huts and benches are cast into the sides of the rock. It is, in some senses, a piece of almost primordial architecture, the kind of thing to excite the phenomenologist in every architect. And , indeed, O’Donnell and Tuomey have cited it as an influence on their nearby Killiney House).

People swim here all year round but on Christmas day group madness seems to take over and half of Dublin goes in. The hardcore line up on the cliff – some dressed as Father Christmas or wearing antlers as if they have just stumbled out of an office party – ready to dive in. No one lasts very long in the water, most taking a few brisk strokes to check they're still alive before heading straight out, hopping up and down on the freezing rocks and turning purple.

A band, along with various food and coffee vans, sets up nearby as well as, inevitably, a stall selling “I swam the 40 ft” T-Shirts. People clutch flasks of whisky or pop bottles of champagne to celebrate the returning sensation in their legs. There is an almost continuous stream of people clutching towels filing up and down the approach.

It’s a bizarre sight, hundreds of people bobbing in the winter sea and standing on the rocks, a point when, briefly, the 40 Ft becomes the most popular public space in Dublin Bay. It is like a waterborne version of Trafalgar Square on New Years Eve, a place transformed by event into a piece of instant urbanism.

To the forlorn sight of abandoned new year fir trees can be added another symbol of post Christmas comedown: the bedraggled Santa hat floating in the water.

And yes, I did go in.